A Preliminary Study on the Ornamentation Patterns of Ganoid Scales in Some Mesozoic Actinopterygian Fishes
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Lecture 6 – Integument ‐ Scale • a Scale Is a Small Rigid Plate That Grows out of an Animal’ S Skin to Provide Protection
Lecture 6 – Integument ‐ Scale • A scale is a small rigid plate that grows out of an animal’s skin to provide protection. • Scales are quite common and have evolved multiple times with varying structure and function. • Scales are generally classified as part of an organism's integumentary system. • There are various types of scales according to shape and to class of animal. • Although the meat and organs of some species of fish are edible by humans, the scales are usually not eaten. Scale structure • Fish scales Fish scales are dermally derived, specifically in the mesoderm. This fact distinguishes them from reptile scales paleontologically. Genetically, the same genes involved in tooth and hair development in mammals are also involved in scale development. Earliest scales – heavily armoured thought to be like Chondrichthyans • Fossil fishes • ion reservoir • osmotic control • protection • Weighting Scale function • Primary function is protection (armor plating) • Hydrodynamics Scales are composed of four basic compounds: ((gmoving from inside to outside in that order) • Lamellar bone • Vascular or spongy bone • Dentine (dermis) and is always associated with enamel. • Acellular enamel (epidermis) • The scales of fish lie in pockets in the dermis and are embeded in connective tissue. • Scales do not stick out of a fish but are covered by the Epithelial layer. • The scales overlap and so form a protective flexible armor capable of withstanding blows and bumping. • In some catfishes and seahorses, scales are replaced by bony plates. • In some other species there are no scales at all. Evolution of scales Placoid scale – (Chondricthyes – cartilagenous fishes) develop in dermis but protrude through epidermis. -
The Strawberry Bank Lagerstätte Reveals Insights Into Early Jurassic Lifematt Williams, Michael J
XXX10.1144/jgs2014-144M. Williams et al.Early Jurassic Strawberry Bank Lagerstätte 2015 Downloaded from http://jgs.lyellcollection.org/ by guest on September 27, 2021 2014-144review-articleReview focus10.1144/jgs2014-144The Strawberry Bank Lagerstätte reveals insights into Early Jurassic lifeMatt Williams, Michael J. Benton &, Andrew Ross Review focus Journal of the Geological Society Published Online First doi:10.1144/jgs2014-144 The Strawberry Bank Lagerstätte reveals insights into Early Jurassic life Matt Williams1, Michael J. Benton2* & Andrew Ross3 1 Bath Royal Literary and Scientific Institution, 16–18 Queen Square, Bath BA1 2HN, UK 2 School of Earth Sciences, University of Bristol, Bristol BS8 2BU, UK 3 National Museum of Scotland, Chambers Street, Edinburgh EH1 1JF, UK * Correspondence: [email protected] Abstract: The Strawberry Bank Lagerstätte provides a rich insight into Early Jurassic marine vertebrate life, revealing exquisite anatomical detail of marine reptiles and large pachycormid fishes thanks to exceptional preservation, and especially the uncrushed, 3D nature of the fossils. The site documents a fauna of Early Jurassic nektonic marine animals (five species of fishes, one species of marine crocodilian, two species of ichthyosaurs, cephalopods and crustaceans), but also over 20 spe- cies of insects. Unlike other fossil sites of similar age, the 3D preservation at Strawberry Bank provides unique evidence on palatal and braincase structures in the fishes and reptiles. The age of the site is important, documenting a marine ecosystem during recovery from the end-Triassic mass extinction, but also exactly coincident with the height of the Toarcian Oceanic Anoxic Event, a further time of turmoil in evolution. -
1 Lab External Morphology and Taxonomy
External Morphology Gross Anatomy: Fins Dorsal & Taxonomy Caudal Lab 1 Anal Pectoral Pelvic 1. Median fins (dorsal, anal, adipose, caudal) 2. Paired fins (pectoral and pelvic) – abdominal vs. thoracic placement 3. Fish use different fins for locomotion (wrasses use pectorals, triggerfish use median fins, tunas use caudal fins) 4. Fins are constructed of either radial cartilage (sharks) or bony rays (most fishes) Caudal Fin Shape Body Shape body shape can predict ecology: • fusiform tend to be fast swimming and inhabit the upper portions of the water column • compressed tend to be good maneuvers • elongate tend to be good accelerators Caudal fin shape can predict fish ecology (ambush • anguilliform and globiform tend to be poor swimmers and benthic predator, continuous swimmer, burst swimmer, benthic dweller, etc.) • depressed tend to be benthic Mouth Morphology Eyes Mouth morphology can be used to infer what types of prey are eaten (piscivores, planktivores, invertebrate eaters, herbivores, etc.) and where in the water column the prey are consumed Inferior Subterminal 1. placement and size may indicate something about the ecology of the fish 2. some fish (e.g., mudskippers) are adapted to see both in and outside of water 3. stalked eyes in deepwater fish are one adaptation to gather light Terminal Superior 1 Countershading Lateral Line • countershading is a feature common to most fish, especially those that inhabit the surface and midwater • fish are dark on the dorsal region and light on the ventral region • functions as camouflage in open water 1. lateral line extends along the midsection of the fish 2. can be continuous or broken 3. -
Threat-Protection Mechanics of an Armored Fish
JOURNALOFTHEMECHANICALBEHAVIOROFBIOMEDICALMATERIALS ( ) ± available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/jmbbm Research paper Threat-protection mechanics of an armored fish Juha Songa, Christine Ortiza,∗, Mary C. Boyceb,∗ a Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, RM 134022, Cambridge, MA 02139, USA b Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA ARTICLEINFO ABSTRACT Article history: It has been hypothesized that predatory threats are a critical factor in the protective functional design of biological exoskeletons or “natural armor”, having arisen through evolutionary processes. Here, the mechanical interaction between the ganoid armor of the predatory fish Polypterus senegalus and one of its current most aggressive threats, a Keywords: toothed biting attack by a member of its own species (conspecific), is simulated and studied. Exoskeleton Finite element analysis models of the quadlayered mineralized scale and representative Polypterus senegalus teeth are constructed and virtual penetrating biting events simulated. Parametric studies Natural armor reveal the effects of tooth geometry, microstructure and mechanical properties on its ability Armored fish to effectively penetrate into the scale or to be defeated by the scale, in particular the Mechanical properties deformation of the tooth versus that of the scale during a biting attack. Simultaneously, the role of the microstructure of the scale in defeating threats as well as providing avenues of energy dissipation to withstand biting attacks is identified. Microstructural length scale and material property length scale matching between the threat and armor is observed. Based on these results, a summary of advantageous and disadvantageous design strategies for the offensive threat and defensive protection is formulated. -
A Comparative Study of Piscine Defense the Scales of Arapaima
Journal of the mechanical behavior of biomedical materials xx (xxxx) xxxx–xxxx Contents lists available at ScienceDirect Journal of the Mechanical Behavior of Biomedical Materials journal homepage: www.elsevier.com/locate/jmbbm A comparative study of piscine defense: The scales of Arapaima gigas, Latimeria chalumnae and Atractosteus spatula ⁎ Vincent R. Shermana, Haocheng Quana, Wen Yangb, Robert O. Ritchiec, Marc A. Meyersa,d, a Department of Mechanical and Aerospace Engineering, Materials Science and Engineering Program, University of California San Diego, La Jolla, CA 92093, USA b Department of Materials, ETH Zurich, 8093 Zurich, Switzerland c Department of Materials Science and Engineering, University of California Berkeley, CA 94720, USA d Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA ARTICLE INFO ABSTRACT Keywords: We compare the characteristics of the armored scales of three large fish, namely the Arapaima gigas Scales (arapaima), Latimeria chalumnae (coelacanth), and Atractosteus spatula (alligator gar), with specific focus on Bioinspiration their unique structure-mechanical property relationships and their specialized ability to provide protection from Bouligand predatory pressures, with the ultimate goal of providing bio-inspiration for manmade materials. The arapaima Alligator gar has flexible and overlapping cycloid scales which consist of a tough Bouligand-type arrangement of collagen Coelacanth layers in the base and a hard external mineralized surface, protecting it from piranha, a predator with extremely Arapaima sharp teeth. The coelacanth has overlapping elasmoid scales that consist of adjacent Bouligand-type pairs, forming a double-twisted Bouligand-type structure. The collagenous layers are connected by collagen fibril struts which significantly contribute to the energy dissipation, so that the scales have the capability to defend from predators such as sharks. -
A Synoptic Review of the Vertebrate Fauna from the “Green Series
A synoptic review of the vertebrate fauna from the “Green Series” (Toarcian) of northeastern Germany with descriptions of new taxa: A contribution to the knowledge of Early Jurassic vertebrate palaeobiodiversity patterns I n a u g u r a l d i s s e r t a t i o n zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.) der Mathematisch-Naturwissenschaftlichen Fakultät der Ernst-Moritz-Arndt-Universität Greifswald vorgelegt von Sebastian Stumpf geboren am 9. Oktober 1986 in Berlin-Hellersdorf Greifswald, Februar 2017 Dekan: Prof. Dr. Werner Weitschies 1. Gutachter: Prof. Dr. Ingelore Hinz-Schallreuter 2. Gutachter: Prof. Dr. Paul Martin Sander Tag des Promotionskolloquiums: 22. Juni 2017 2 Content 1. Introduction .................................................................................................................................. 4 2. Geological and Stratigraphic Framework .................................................................................... 5 3. Material and Methods ................................................................................................................... 8 4. Results and Conclusions ............................................................................................................... 9 4.1 Dinosaurs .................................................................................................................................. 10 4.2 Marine Reptiles ....................................................................................................................... -
Body-Shape Diversity in Triassic–Early Cretaceous Neopterygian fishes: Sustained Holostean Disparity and Predominantly Gradual Increases in Teleost Phenotypic Variety
Body-shape diversity in Triassic–Early Cretaceous neopterygian fishes: sustained holostean disparity and predominantly gradual increases in teleost phenotypic variety John T. Clarke and Matt Friedman Comprising Holostei and Teleostei, the ~32,000 species of neopterygian fishes are anatomically disparate and represent the dominant group of aquatic vertebrates today. However, the pattern by which teleosts rose to represent almost all of this diversity, while their holostean sister-group dwindled to eight extant species and two broad morphologies, is poorly constrained. A geometric morphometric approach was taken to generate a morphospace from more than 400 fossil taxa, representing almost all articulated neopterygian taxa known from the first 150 million years— roughly 60%—of their history (Triassic‒Early Cretaceous). Patterns of morphospace occupancy and disparity are examined to: (1) assess evidence for a phenotypically “dominant” holostean phase; (2) evaluate whether expansions in teleost phenotypic variety are predominantly abrupt or gradual, including assessment of whether early apomorphy-defined teleosts are as morphologically conservative as typically assumed; and (3) compare diversification in crown and stem teleosts. The systematic affinities of dapediiforms and pycnodontiforms, two extinct neopterygian clades of uncertain phylogenetic placement, significantly impact patterns of morphological diversification. For instance, alternative placements dictate whether or not holosteans possessed statistically higher disparity than teleosts in the Late Triassic and Jurassic. Despite this ambiguity, all scenarios agree that holosteans do not exhibit a decline in disparity during the Early Triassic‒Early Cretaceous interval, but instead maintain their Toarcian‒Callovian variety until the end of the Early Cretaceous without substantial further expansions. After a conservative Induan‒Carnian phase, teleosts colonize (and persistently occupy) novel regions of morphospace in a predominantly gradual manner until the Hauterivian, after which expansions are rare. -
Semionotiform Fish from the Upper Jurassic of Tendaguru (Tanzania)
Mitt. Mus. Nat.kd. Berl., Geowiss. Reihe 2 (1999) 135-153 19.10.1999 Semionotiform Fish from the Upper Jurassic of Tendaguru (Tanzania) Gloria Arratial & Hans-Peter Schultze' With 12 figures Abstract The late Late Jurassic fishes collected by the Tendaguru expeditions (1909-1913) are represented only by a shark tooth and various specimens of the neopterygian Lepidotes . The Lepidotes is a new species characterized by a combination of features such as the presence of scattered tubercles in cranial bones of adults, smooth ganoid scales, two suborbital bones, one row of infraorbital bones, non-tritoral teeth, hyomandibula with an anteriorly expanded membranous outgrowth, two extrascapular bones, two postcleithra, and the absence of fringing fulcra on all fins. Key words: Fishes, Actinopterygii, Semionotiformes, Late Jurassic, East-Africa . Zusammenfassung Die spätoberjurassischen Fische, die die Tendaguru-Expedition zwischen 1909 und 1913 gesammelt hat, sind durch einen Haizahn und mehrere Exemplare des Neopterygiers Lepidotes repräsentiert. Eine neue Art der Gattung Lepidotes ist be- schrieben, sie ist durch eine Kombination von Merkmalen (vereinzelte Tuberkel auf den Schädelknochen adulter Tiere, glatte Ganoidschuppen, zwei Suborbitalia, eine Reihe von Infraorbitalia, nichttritoriale Zähne, Hyomandibulare mit einer membra- nösen nach vorne gerichteten Verbreiterung, zwei Extrascapularia, zwei Postcleithra und ohne sich gabelnde Fulkren auf dem Vorderrand der Flossen) gekennzeichnet. Schlüsselwörter: Fische, Actinopterygii, Semionotiformes, Oberer Jura, Ostafrika. Introduction margin, crescent shaped lateral line pore, and the number of scales in vertical and longitudinal At the excavations of the Tendaguru expeditions rows), and on the shape of teeth (non-tritoral) . (1909-1913), fish remains were collected to- However, the Tendaguru lepidotid differs nota- gether with the spectacular reptiles in sediments bly from L. -
Who Ate the Ammonite? Activity Adapted from Earth Learning Idea, Earth Science Education Unit, Keele University
Who Ate the Ammonite? Activity adapted from Earth Learning Idea, Earth Science Education Unit, Keele University Suitable for KS2 – Year 3 rocks and fossils topic, Year 4 food chains topic The aim of this activity is for students to create a food web of Jurassic aged organisms using the feeding information provided and stickers/cut out images. Once the food web has been completed children should work out which creature could have eaten the ammonite. Learning outcomes • Understand how organisms can become fossils • Understand that different organisms lived on Earth 200 million years ago, some of which can be found as fossils. • Understand that climate, sea level and position of continents can change over millions of years. • Build up a food web in trophic levels from producer to consumer. • Realise that energy is transferred up the trophic levels from producer to consumer. • Realise that trophic levels do not equate to where the animal lives in the water column. Background information (discuss with students before starting activity) • When was the Jurassic period? • What was the climate like in Britain during this time? The Jurassic period was between 201 and 145 million years ago (Ma). At this time Britain lay between 30° - 40° north of the equator (modern day - between 50° - 60°). Its climate would’ve been much warmer and more humid. Sea levels were also higher in the Jurassic which meant that much of Britain was covered by a warm shallow sea. Can demonstrate using Jurassic paleogeography map. • How do animals turn into fossils? Fossils are the preserved remains from animals and plants that used to live on Earth. -
A Speiballen from the Lower Jurassic Posidonia Shale of South Germany
N. Jb. Geol. Paläont. Abh. 267/1, 117–124 Article Published online December 2012 A Speiballen from the Lower Jurassic Posidonia Shale of South Germany Detlev Thies and Rolf Bernhard Hauff with 1 figure Thies, D. & hauff, R.B. (2013): A Speiballen from the Lower Jurassic Posidonia Shale of South Ger- many. – N. Jb. Geol. Paläont. Abh., 267: 117–124; Stuttgart. Abstract: A Speiballen (regurgitated compacted mass of indigestible stomach contents) from the Lower Jurassic Posidonia Shale of Ohmden, South Germany contains remains of four specimens of the actinopterygian Dapedium sp., the specific identity of which remains obscure, and a lower jaw of a specimen identified as Lepidotes sp. A list of five suitable characters is proposed to distinguish fossil Speiballen containing specimens from other vertebrate fossils. Large, potentially piscivorous animals in the Posidonia Shale ecosystem comprise chondrichthyans (Hybodus), other actinoptery- gians (pachycormiforms) and marine reptiles (crocodilians, ichthyosaurs, plesiosaurs). Only juvenile ichthyosaurs (Stenopterygius) are known to have preyed on Dapedium. Available data are, however, insufficient to clearly identify the Speiballen producer. The heavy scale armour of basal neoptery- gians such as Dapedium undoubtedly hampered digestion of these fishes and in this way provided additional protection against predators. Key words: Jurassic, Fossillagerstätte, Holzmaden, ecosytem, predation. 1. Introduction English equivalent of the German term ‘Speiballen’ (or ‘Gewölle’, which means the same) does not seem to Speiballen are understood to be regurgitated com- exist. Burrow & Turner (2010) described an assem- pacted masses of indigestible stomach contents. They blage of skeletal element, tooth whorls and scales of are released in the form of gastric pellets through the the acanthodian Nostolepis scotica from the Early De- pharynx in contrast to faeces that represent intestinal vonian of Scotland comparable in terms of taphonomy contents that are excreted through the anus. -
A Revision of the Pycnodontid Fish Coelodus Subdiscus Wenz 1989, from the Early Cretaceous of Montsec (Lleida, Spain)
Treb. Mus. Geol. Barcelona, 8: 33-65 (1999) A revision of the pycnodontid fish Coelodus subdiscus Wenz 1989, from the Early Cretaceous of Montsec (Lleida, Spain) Jurgen KRIWET*, Francisco José POYATOARIZA** and Sylvie WENZ*** RESUMEN KRIWET, J., POYATO-ARTZA, F.J. y WENZ, S. Revision del pez pycnodóntido Coelodus subdiscus Wenz 1989, del Cretácico inferior del Montsec (Lleida, España). La revision de Coelodus subdiscus Wenz 1989 (Cretácico inferior del Montsec, Lleida) proporciona nueva información sobre su anatomIa, especialmente sobre los esqueletos craneal y caudal y sobre la cloaca. El hueso parietal presenta una exten- sión digitada, el proceso parietal, y parece constar de dos partes fusionadas, parietal y supratemporal. Se discute la identificación del hueso en el margen posterodorsal de la órbita. Descrito como dermopterótico, parece consistir en un complejo de dermopterótico más dermosfenótico. Ello se evidencia por la union en este hueso de los canales sensoriales infraorbitario y supraorbitario. Se figuran las denticiones prearticular y vomeriana, y se indica la presencia de grandes dientes branquiales con forma de gancho. Se describen en detalle, por primera vez, el esqueleto caudal, las escamas del horde del cuerpo y las que forman la cloaca. Para evitar forzar homo- logIas, adn por establecer, con los teleOsteos, se utilizan para el endoesqueleto cau- dal los términos "elementos epi- e hipocordales". Hay 4 epi- y al menos 12 ele- mentos hipocordales, y dos grandes urodermales, estrechamente articulados. Las fulcras están ausentes. La cloaca está formada por una escama diferenciada anterior y dos posteriores. Se presenta una revision taxonómica y una nueva diagnosis de Coelodus subdiscus. -
FISH BIOLOGY (2 UNITS) This Course Is Taught by Three (3) Lecturers
LECTURE NOTE ON FIS 301 FIS 301: FISH BIOLOGY (2 UNITS) This Course is taught by three (3) lecturers – Dr. I.T Omoniyi, Dr. F.I. Adeosun and Dr. A.A. Akinyemi. The Course Synopsis is further outlined on lecture basis as follows: Lectures 1 – 3: Gross external anatomy of typical bony and cartilaginous fishes. Lectures 4 – 5: Gross internal anatomy of typical bony and cartilaginous fishes. Lectures 6 – 7: Anatomy of systems and basic functions Lectures 8 – 9: Reproductive biology treated under fecundity Lectures 10 – 12: Embryology/life history of fish. GROSS EXTERNAL ANATOMY By way of introduction, basic diagnostic features of fish need to be identified. 1. Fishes are cold blooded/poikilothermic animals i.e their body temperature varying passively in accordance with the ambient temperature (surrounding water temperature). Although, fishes as a group can tolerate wide range of temperature from just below O0C to 450C, individual species generally have a preferred or optimum as well as a more restricted temperature range. For example, salmonids inhabit water with temperature range from 0-200C. Any change within the optimum range can significant influence the biology as related to the anatomy. 2. The adoption of aquatic habit has other implications for the structure and physiology of fish. For instance, it makes the streamlining and shaping of the body an important pre-requisite 1 for success in aquatic life. The shapes range from ovoid to torpedo-like or fusiform shape. This is due to the higher density of water than air. 3. Respiration assumes a greater important through the gills when compared to terrestrial th animals because water contains 1/20 of 02 available in air.